The first widely distributed version of Unix,
released unsupported by Bell Labs in 1978. The term is used adjectivally
to describe Unix features and programs that date from that release, and are
thus guaranteed to be present and portable in all Unix versions (this was
the standard gauge of portability before the POSIX and IEEE 1003
standards). Note that this usage does not derive from
the release being the “seventh version of
Unix”; research Unix
at Bell Labs has traditionally been numbered according to the edition of
the associated documentation. Indeed, only the widely-distributed Sixth
and Seventh Editions are widely known as V[67]; the OS that might today be
known as ‘V10’ is instead known in full as “Tenth Edition
Research Unix” or just “Tenth Edition” for short. For
this reason, “V7” is often read by cognoscenti as
“Seventh Edition”. See BSD,
Unix. Some old-timers impatient with
commercialization and kernel bloat still maintain that V7 was the Last True
Unix.